android - About Changing The Background -

the animation put application has circle. want background change when click on circle. when background changing, freezes second. how can fix this

public class main extends activity implements animationlistener {     imageview imageview, imageview2;    button rotatescale, countdown;     // animasyon    animation animasyonumuz, animasyonumuz2;     @override    protected void oncreate(bundle savedinstancestate) {           // todo auto-generated method stub           super.oncreate(savedinstancestate);           setcontentview(r.layout.main);            imageview = (imageview) findviewbyid(r.id.imageview1);           imageview2 = (imageview) findviewbyid(r.id.imageview2);           rotatescale = (button) findviewbyid(r.id.mainb);           countdown = (button) findviewbyid(r.id.countdown);           countdowntimer countdownexample = new countdownexample(30000, 1000);           countdownexample.start();              // animasyonu yükleme     animasyonumuz = animationutils.loadanimation(getapplicationcontext(),                        r.anim.animasyonkadran1);            // animasyon listener ı kurma     animasyonumuz.setanimationlistener(this);      animasyonumuz2 = animationutils.loadanimation(getapplicationcontext(),             r.anim.animasyonimlec1);       animasyonumuz2.setanimationlistener(this);            // butona dokulduğunda yapılacaklar     imageview.setonclicklistener(new view.onclicklistener() {                  @override                  public void onclick(view v) {                        // animasyonu başlatma                        imageview.startanimation(animasyonumuz);                        imageview2.startanimation(animasyonumuz2);                        imageview.setonclicklistener(new onclicklistener() {                          @override                         public void onclick(view v) {                             // todo auto-generated method stub                               imageview.setimageresource(r.drawable.dairebiryesil);                             imageview.setonclicklistener(new onclicklistener() {                                  @override                                 public void onclick(view v) {                                     // todo auto-generated method stub                                     imageview.setimageresource(r.drawable.daireikiyesil);                                     imageview.setonclicklistener(new onclicklistener() {                                          @override                                         public void onclick(view v) {                                             // todo auto-generated method stub                                             imageview.setimageresource(r.drawable.daireucyesil);                                             imageview.setonclicklistener(new onclicklistener() {                                                  @override                                                 public void onclick(view v) {                                                     // todo auto-generated method stub                                                     imageview.setimageresource(r.drawable.dairedortyesil);                                                 }                                             });                                         }                                     });                                 }                             });                         }                     });                  }           });       }